"to support this privileged class as long as they kept up their end of the bargain with effective rituals. But after 650, deforestation, erosion, and soil exhaustion began reducing crop yields. The working classes, the farmers and monument builders, may have suffered increasing hunger and disease, even as the rulers hogged an ever-larger share of resources. The society was heading for a crisis. Diamond writes: "We have to wonder why the kings and nobles failed to recognize and solve these seemingly obvious problems undermining their society. Their attention was evidently focused on their short-term concerns of enriching themselves, waging wars, erecting monuments, competing with each other, and extracting enough food from the peasants to support all those activities." (If this sounds familiar, I would note that archaeology is thick with cautionary tales that speak directly to the twenty-first century.)"